1.  Thyrotoxic periodic paralysis (TPP) is a condition featuring attacks of muscle weakness in the presence of hyperthyroidism. This study was conducted to know the incidence and method of prevention of thyrotoxic periodic paralysis in patients with thyrotoxicosis treated with radioactive iodine.200 Patients with thyrotoxicosis after withholding anti thyroid drugs were treated with radioactive iodine from 2006 September to 2008 March were analysed for symptoms of periodic paralysis post radio iodine treatment setting. Out of 200 patients 100 patients included in control group were educated about thyrotoxic periodic paralysis and were asked to take natural potassium supplements like coconut water among which 83 patients were given natural supplementation with high potassium diet and the remaining 17 patients received syrup potchlor 2 mL twice daily based on the severity of the thyrotoxicosis. Other 100 patients who were in the test group were not supplemented with potassium and not educated about thyrotoxic periodic paralysis.

Out of the 100 patients who did not receive any potassium supplementation 44 patients presented with generalised muscle weakness in the first 4 weeks post radio iodine therapy, 5 patients presented with periodic paralysis and 1 patient expired due to arrhythmia with ECG evidence of hypokalemic changes, Serum potassium levels less than 3 mEqv/L. Among the rest of the 100 patients who received oral supplementation only 1 presented with symptoms suggestive of thyrotoxic periodic paralysis. The incidence of thyrotoxic periodic paralysis is high in the first four to six weeks post radio iodine therapy because of withholding antithyroid drugs as well as initial radio iodine induced thyroiditis. Oral natural potassium supplementation post radio iodine therapy for initial 6 weeks is an adequate prophylactic measure to prevent the morbidity and remote mortality from thyrotoxic hypokalemic periodic paralysis in patients being treated with radioactive iodine.

Key Words: Thyrotoxic Periodic Paralysis, Hypokalemia, Thyrotoxicosis.